1
|
Lavín C, Vega MV, Velasco AM. Photoionization cross sections and asymmetry parameters for the valence shell of methanol. J Phys Chem A 2012; 116:11913-9. [PMID: 23153107 DOI: 10.1021/jp3103723] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Theoretical cross sections for photoionization of the methanol valence orbitals in covering a region up to 80 eV beyond the first ionization potential are reported. The molecular quantum defect orbital, MQDO, method, which has proved to be reliable in previous applications to molecular photoionization, has been used. To our knowledge, predictions of electronic partial cross section profiles on this molecule are made here for the first time, and we are not aware of any reported experimental data. Partial cross sections for production of parent and fragment ions of methanol have also been calculated and compared with previous measurements. In addition, the MQDO method has been used to calculate the angular distribution of photoelectrons for the valence orbitals of methanol over the 11-50 eV photon energy range. Our results are compared with experimental data, showing a good agreement in most cases. We hope that the present results might be of use in atmospheric and interstellar chemistry, where this molecule plays an important role.
Collapse
Affiliation(s)
- C Lavín
- Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, Spain
| | | | | |
Collapse
|
2
|
Vega MV, Lavín C, Velasco AM. Angular distribution of photoelectrons in small molecules: a molecular quantum defect calculation. J Chem Phys 2012; 136:214308. [PMID: 22697544 DOI: 10.1063/1.4725536] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The molecular quantum defect orbital (MQDO) method, previously used in the determination of molecular photoionization cross sections, is applied here to calculate the angular distribution of photoelectrons arising from the molecular photoionization. Calculations are performed for the ionization from outer valence orbitals of HF, H(2)O, NH(3), N(2)O, and H(2)CO molecules. The results are compared with previous measurements and with theoretical curves found in the literature. Profiles of the angular distribution parameter as a function of photoelectron energy covering a range from the photoionization threshold to 120 eV are presented for the above molecules. The energy dependence of the angular distributions predicted by the MQDO calculations agrees fairly well with predictions from more sophisticated theories and with observed results.
Collapse
Affiliation(s)
- M V Vega
- Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | | | | |
Collapse
|
3
|
Zhen C, Hu YH, Zhou XG, Liu SL. Dissociation Dynamics of Nitrous Oxide from Jet-cooling Absorption Spectrum in 142.5–147.5 nm. CHINESE J CHEM PHYS 2011. [DOI: 10.1088/1674-0068/24/03/267-274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
4
|
Electron diffraction with bound electrons: The structure sensitivity of Rydberg Fingerprint Spectroscopy. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.02.041] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
5
|
Vega MV, Lavín C, Velasco AM, Martín I. Oscillator strengths and photoionisation cross sections for Rydberg transitions in acetaldehyde. Theor Chem Acc 2010. [DOI: 10.1007/s00214-010-0729-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
6
|
Velasco AM, Lavín C, Martín I, Melin J, Ortiz JV. Partial photoionization cross sections of NH4 and H3O Rydberg radicals. J Chem Phys 2009; 131:024104. [DOI: 10.1063/1.3168397] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
|
7
|
Lavín C, Velasco AM, Vega MV, Marín I, Pitarch-Ruiz J, Sánchez Marín J. Theoretical study of spectral intensities of formaldehyde in the discrete and continuum regions. J Phys Chem A 2009; 113:7155-60. [PMID: 19489599 DOI: 10.1021/jp900464q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Theoretical absorption oscillator strengths for transitions involving Rydberg states in molecular formaldehyde as well as cross sections for photoionization Rydberg channels associated with the production of the lowest parent ion electronic state are reported. The calculations have been performed with the molecular quantum defect orbital (MQDO) method. A test on the MQDO f values has been its comparison with previous experiments and calculations and its compliance with the expected systematic trends along the Rydberg series. The use of the MQDO method as an alternative to ab initio methods, which find serious difficulties in calculating spectral intensities in formaldehyde, is proposed. We hope that the spectroscopic data, many of them reported here for the first time, may be useful for the interpretation of the vacuum ultraviolet spectrum of this molecule.
Collapse
Affiliation(s)
- C Lavín
- Departamento de Química Física y Química Inorgánica, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | | | | | | | | | | |
Collapse
|
8
|
Similarities in the continuous states of the group of halogenated methanes CH3X (X=Cl, Br, I): Molecular quantum defect orbital (MQDO) cross section calculations for allowed photoionization channels. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.05.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
9
|
Vieira RC, Falvey DE. Photoinduced Electron-Transfer Reactions in Two Room-Temperature Ionic Liquids: 1-Butyl-3-methylimidazolium Hexafluorophosphate and 1-Octyl-3-methylimidazolium Hexafluorophosphate. J Phys Chem B 2007; 111:5023-9. [PMID: 17474706 DOI: 10.1021/jp0630471] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photoinduced electron transfer in two room-temperature ionic liquids, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF(6)) and 1-octyl-3-methylimidazolium hexafluorophosphate (OMIM-PF(6)), has been investigated using steady-state fluorescence quenching of 9,10-dicyanoanthracene with a series of single electron donors. From these fluorescence quenching rates, reorganization energy (lambda) values and k(diff) values can be derived from a Rehm-Weller analysis. In many cases, these fluorescence quenching reactions occur at rates larger than what would be expected based on the Smoluchowski equation. In addition, lambda values of 10.1 kcal/mol and 16.3 kcal/mol for BMIM-PF(6) and OMIM-PF(6), respectively, have been determined.
Collapse
Affiliation(s)
- Rebecca C Vieira
- Department of Chemistry and Biochemistry, University of Maryland at College Park, College Park, Maryland 20742, USA
| | | |
Collapse
|
10
|
Velasco AM, Martín * I, Lavín C, Bustos E. Radiative lifetimes for the A2Σ+(v′ = 0–7) and D2Σ+(v′ = 0–5) Rydberg states of NO. Mol Phys 2005. [DOI: 10.1080/00268970500052296] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
Lavı́n C, Velasco A, Martı́n I, Bustos E. MQDO oscillator strengths and emission coefficients for electronic transitions in N2 and NO. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.06.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
12
|
Velasco AM, Martín I, Pitarch-Ruiz J, Sánchez-Marín J. MRSDCI Vertical Excitation Energies and MQDO Intensities for Electronic Transitions to Rydberg States in H2S. J Phys Chem A 2004. [DOI: 10.1021/jp049415n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Mayor E, Velasco AM, Martín I. Photodissociation Rate Constants for VUV Processes of CF3Cl and CF2Cl2 in the Upper Atmosphere. A MQDO Study. J Phys Chem A 2004. [DOI: 10.1021/jp049718h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- E. Mayor
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | - A. M. Velasco
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | - I. Martín
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| |
Collapse
|
14
|
McNavage W, Dailey W, Dai HL. The ν1 and ν2 vibrational bands of the OCCN radical detected through time-resolved Fourier transform IR emission spectroscopy. CAN J CHEM 2004. [DOI: 10.1139/v04-041] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Through monitoring the IR emission from vibrationally excited radicals generated by exothermic photolysis reactions, the CN stretch (ν1) and the CO stretch (ν2) vibrational bands of the cyanooxomethyl radical (OCCN) have been observed for the first time at 2093 cm1 and 1774 cm1, respectively. The OCCN radical was produced through 193 nm photolysis of methyl cyanoformate (NCC(O)OCH3), carbonyl cyanide (NCC(O)CN), and pivaloyl cyanide (NCC(O)C(CH3)3). The IR emission spectra were recorded by using nanosecond time-resolved Fourier transform IR emission spectroscopy. Assignments of the spectral peaks were made based on observed time and pressure dependences of IR emission intensities, ab initio calculations, and two-dimensional cross-spectra correlation analysis. Key words: radical, cyanooxomethyl, OCCN, time-resolved vibrational spectroscopy, FTIR, substituted carbonyl dissociation reactions, two-dimensional cross-spectra correlation analysis
Collapse
|
15
|
Bustos E, Velasco AM, Martín I, Lavín C. Rydberg Series as Ionization Channels: Photoabsorption and Photoionization of the Atmospherically Relevant Molecule NO. J Phys Chem A 2004. [DOI: 10.1021/jp022478q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E. Bustos
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
| | - A. M. Velasco
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
| | - I. Martín
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
| | - C. Lavín
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
| |
Collapse
|
16
|
Velasco A, Mayor E, Martı́n I. Intensity calculations of the VUV and UV photoabsorption and photoionisation of CF3Cl. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)01132-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
17
|
|
18
|
Velasco A, Mayor E, Martı́n I. Oscillator strengths and ionisation cross sections for the absorption of CF2Cl2 in the UV and VUV spectral regions. A MQDO study. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00962-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
19
|
Spectral intensities of Rydberg transitions in carbonyl compounds. Formaldehyde, carbonyl fluoride and phosgene. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)01591-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
20
|
Velasco AM, Bustos E, Martín I, Lavín C. Intensities of Vibronic Transitions for the Main Bands Observed in the Electronic Spectrum of Atmospherically Relevant Nitric Oxide. J Phys Chem A 2002. [DOI: 10.1021/jp020444c] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. M. Velasco
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | - E. Bustos
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | - I. Martín
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| | - C. Lavín
- Departamento de Química Física, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain
| |
Collapse
|